Mega-IPOs from SpaceX and others could intensify already 'dangerous' concentration risk in the stock market

The top 10 stocks in the S&P 500 make up almost 40% of the index's weight. If SpaceX, OpenAI, and Anthropic join the index, that could hit 50%.

S&P weighs rule changes that would speed SpaceX’s S&P 500 entry: report

S&P Dow Jones Indices is said to be considering changes to rules governing how companies join the S&P 500 Index (SPX), a move that would potentially fast-track SpaceX’s (SPACE) entry after its IPO.